When renewable energy such as wind power generation and solar power generation spreads, there are concerns that the entire power system becomes unstable due to fluctuations in power generation output. Meanwhile, it is necessary to level the load by changing the output of a conventional thermal power generator. Among the thermal power generators, gas turbine power generation is expected to be able to level fluctuations in renewable energy output, because the startup time is shorter than the coal-fired power generation and the load change rate is also large.
As a technique relating to a gas turbine that drives a power generator and the like, for example, PTL 1 discloses a two-shaft gas turbine which has a first rotation shaft which expands the compressed air sent from a rotary compressor by a combustor and drives the high-pressure turbine by the combustion gas to allow the compressor to autonomously rotate by the driving force, and a second rotation shaft which drives a power generator by a low-pressure turbine installed on a separate shaft downstream the high-pressure turbine.
PTL 2 suggests a method for using a flywheel device as a device for storing energy to achieve a short-time power balance.